Stone-crushing machine



T. G. RENNERFELT. STONE CRUSHING MACHINE.

APPLICATION FILED DEC.12| 191s.

Patented Dec. 28, 1920.

'INVENTOR EM 4% flwmw P T @FFICE.

TUBE GUSTAF RENNERFELT, O33 STOCKI-IOLM, SWEDEN.

STONE-CRUSHING MACHINE.

Specification of Letters Eatent.

Patented Dec. 28, 1920.

Application filed. December 12, 1919. Serial No. 344,308.

To all whom it may concern Be it known that I, Tomi GUSTAF RnNNnn- FELT, subject of the King of Sweden, and resident of Stockholm, Sweden, have invented ccrtain new and useful Improvements in Stone-Crushing Machines, of which the following is a specification.

My invention relates to improvements in stone crushing machines of the type in which stones are crushed between a stationary and a movable jaw. Such machines are frequently damaged by overload, caused for instance by the dropping of a sledge or other piece of steel between the jaws. One of the objects of the invention is to provide a satisfactory safety arrangement for preventing damage to the machine by such overload. Other objects are to provide a machine which also in other respects shall be eliicient, reliable and easily attended.

My invention is illustrated in the accompanying drawing, in which Figure 1 shows a. vertical cross section of the improved stone crusher. Fig. 2 is across sectional view, the section being taken on the line 2 of Fig. 1. A detail called the safety bolt is shown in Fig. 3, and Fig. l shows another detail, a spring.

In the drawing 3 denotes the frame of the machine, 4 the stationary jaw, 5 the movable or oscillating jaw journaled in the frame, (5 the driving shaft formed as a crankshaft, 7 a connecting rod mounted on the crank and joined with the lever 8. Said lever 8 is connected by a hinge 9 to another lever or bar 10, which is fulcrumed by the bearing 11 in the frame. Normally the lever 8 is also secured to the bar 10 by means of the safety bolt 12, so that the lever and the bar act together as one lever so long as the bolt 12 is intact. The jaw 5 is provided with a concave face, and the lower end of the bar is formed with a convex face. A cylindrical roller 14 is loosely mounted between the said two faces. A spring 15 serves to pull the jaw against the roller toward the bar. From the drawing it will now be apparent how oscillating motion is transmitted to the jaw 5 upon rotation of the driving shaft.

The safety bolt is provided, between its head 16 and its screwthread 17, with a narrow incision 18 of a diameter smaller than the core of the screwthread. The bolt goes through the lever 8. and is threaded into the upper part of the bar 10, its end which is proper diameter.

square or hexagonal extending outside of the bar. Between the lever 8 and the head 16 is placed a cupped disk 19 of hardened steel which disk acts as a spring. The hinge 9 is located in about the same plane as the disk 19, so that the force acting on the bolt when the machine operates is directed along the center line of the bolt, which therefore is subjected merely to tension but not to bending.

In my Patent No. 11 5581, dated June 1, 1915, is described a safety arrangement e1nbodying a lever formed in two parts held together by a hinge and b a safety bolt. In practical operation this arrangement was not satisfactory in that the bolt frequently broke for a legitimate load. This was due partly to the fact that the bolt was exposed not only to tension but also to some bending, which made it difiicult to determine its It was also, and mainly,- due to the fact that the bolt would stretch under the influence of a great though not abnormal load, and the stretching of the bolt would cause a loose play between the two parts of the lever. The loose play would cause shocks on the bolt, so that it ruptured for a load which was smaller than overload. This diiliculty is now remedied by the above described construction, in which the bolt 12 is subjected merely to tension, and in which there is no loose play in the connection between the lever B and the bar 10. The diameter of the incision 18 is determined so that the bolt is strong enough to transmit any normal strain but is relatively weaker than any other part of the machine so that it will break for an overload, and thus save inexpensive part such as the frame or crankshaft. A heavy strain on the bolt, not great enough to cause its rupture, will compress the spring 19 so that the bolt does not become stretched. Since the incision 18 is very narrow, the spring 19 need not possess any great flexibility. It

should, however, be of great strength, and is therefore preferably constructed, as shown,

in the shape of a cupped disk of hardened steel.

When the bolt breaks the motion of the bar 10 will stop, and the lever 8, driven by the connecting rod, will swing on the hinge 9. The bar 10 is stopped at a certain limit determined by the boss 20 so that its upper end will not encroach on the space necessary for the free motion of the connecting rod.

One part of the broken bolt 12 will be held in the bar so that it cannot become lodged anywhere between the jaw and the bar. It is easily removed from the bar by means of a wrench applied to its projecting square end, and after a new safety bolt is inserted the machine is again ready for operation.

The frame is provided with lugs 21, 21,

arranged to support both ends of the roller 14 while the machine is being assembled. In order to save space the ends of the roller are reduced in diameter so that they form shanks 22, :22.

In order that the crushed stones may be ejected from the machine in suitable direction a bucket 23 is attached to the lower end of the 5. This bucket is exposed to much wear, and to facilitate its exchange when worn out it is simply hinged on the rod 24 drawn through lugs in the jaw, the bucket being formed with. a tail 25 which is kept against the jaw by the weight of the bucket.

In the operation of stone crushers it happens sometimes that stones are thrown upward from the gap between the jaws. In order to prevent such stones from falling on the connecting rod or between the jaw and the bar an apron 26 is provided. The apron made of sheet iron is hinged at one edge to the frame 3 by means of a rod 27, its other edge resting on the bearing of the crankshaft. The apron will act as a shield against the stones; when the bearing is to be examined, the apron is turned on the hinge 27 and allowed to rest on the side plate 28.

What I claim is:

1. In a stone crushing machine the com bination of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt passing through the member and securing it to the lever, a spring between the bolt and the member, and. means within the frame for oscillating the lever.

2. In a stone crushing machine the combi nation of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt passing through the member and threaded in the lever, the end of the bolt extending outside of the lever, a spring between the bolt head and the member, and means for oscillating the lever.

3. In a stone crushing machine the combination of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt passing through the member and secur ing it to the lever, the bolt being formed with a groove, a spring between the bolt head and the member, and means for oscillating the lever.

4. The combination of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt formed with a groove passing through the member and securing it to the lever, an elastic cupped disk between the bolt .head and the member, and means for oscillating the lever.

5. The combination of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt passing through the member and securing it to the lever, the bolt arranged so as to be exposed to merely tension, a cupped disk between the bolt head and the member, and means for oscillating the lever.

6. The combination of a frame, a lever fulcrumed in the frame, a member hinged to the lever, a bolt passing through the member and securing it to the lever, means for oscillating the lever, and means within the frame for stopping the lever at a certain limit upon the breaking of the bolt.

7. In a stone crushing machine the combination of a frame, a provided with a concave face journaled in the frame, a lever fulcrumed in the frame, said lever having a convex face, a roller mounted between the said two faces, a lug on each side of the frame, said lugs being arranged to support the roller while assembling the machine, and means for oscillating the lever.

8. In a stone crushing machine the combination of a frame, a jaw journaled in the frame, rod through the jaw, a bucket hinged on the rod, said bucket being provided with a tailarranged to rest against the jaw and thus hold the bucket in proper position relatively to the jaw, and means for oscillating the jaw.

Signed at Stockholm. Sweden, this 20th day of November, A. D. 1919.

TUBE GUSTAF RENNERFELT.

Witnesses:

Euro ALLE Lor, M. E. Asrnrr. 

